Some people say that certain genre movies are just silly bits of throwaway entertainment without any depth, and they couldn't be more wrong. One of the great things about sci-fi and horror is that they can address really interesting, important, and complex themes in an accessible, fun, and unusual way, all while keeping us thrilled, intrigued, or even scared.
Fear and violence are only the most obvious, too, as there are also great films about exploration, colonialism, politics, class, history, gender, race, the body...
The list goes on.
Sometimes the treatment of the ideas is incredibly subtle, sophisticated, and thought-provoking, and can stay with viewers for a long time, maybe even helping them reimagine the way they understand the world.
Other films, though, whilst they still have important things to say, are not subtle at all. Rather than suggesting or hinting at a theme, they put the main idea front and centre, dripping with gore and screaming its meaning at you with the total opposite of restraint.
Subtlety, after all, isn't always a virtue. What's wrong with being clear and communicating exactly what you mean?